The need for preventing the freezing of water in residential water systems is well known. Upon freezing, water/ice expands, ultimately rupturing the pipes. The resulting damage can be quite extensive; the repair can be quite expensive.
In northern climates where extended periods of sub-freezing temperatures are encountered rather drastic protection measures are necessary. Such measures include the burying of pipes, insulation of pipes, draining of exposed sections of pipes with the onset of the freezing weather season, etc.
In southern, more temperate climates, such measures are seldom employed. In such climates, freezing conditions are infrequent and of short duration. However, they do occur. A common practice to prevent freezing in the pipes when conditions conducive thereto are forecast is to partially open a valve in the system to permit a continuous water flow in the system. While effective, such a practice has drawbacks. It is exceedingly wasteful of water. It depends upon someone being present to be aware of the forecast and take remedial action.
To avoid such drawbacks, a number of devices have been developed to automatically initiate the flow of water with the onset of freezing conditions and stop the flow of water when the freezing conditions have passed. Such a device is shown in U.S. Pat. No. 3,369,556. That device is a valve actuated by a change in the temperature of the atmosphere outside the water pipe. In southern climates, while the atmospheric temperature may at times drop below freezing, the period of low temperature is frequently of insufficient duration to cause freezing of water in the pipes. Thus, this device would initiate the flow of water long before necessary or, at times, when unnecessary to prevent freezing in the pipes.
Several devices have been developed to be attached to the end of a water faucet, which devices are actuated by a drop in temperature to initiate a flow of water. U.S. Pat. Nos. 3,446,226 and 4,205,698 are examples of such devices. Operation of these devices depend on ambient temperatures rather than water temperature and prevent the normal use of the faucet when attached.
It is an object of this invention to provide an improved freeze protection valve assembly which initiates the flow of water in a water system as the temperature of the water approaches freezing and wherein waste of water is minimized and no interference with the normal use of the water system is encountered. Other objects will become apparent from the description of the invention.